Feeding mechanism for sewing machines



NOV- 14, 1933- H. F. GRUMAN FEEDING MECHANISM FOR SEWING MACHINES original Filed Jan. 51, 1931 2 Sheets-Sheet l Snventor,

2 Sheets-Sheet, 2

-H. F. GRUMAN Gttomeg |HHOHHMIJINIII.

Original Filed Jan. 31, 1931 FEEDING MECHANISM FOR SEWING MACHINES Nov. 14, 1933.

5 to provide suchamechanism which can bereadilyV 11.y A slide block 23 is freely mounted yon the 10 40 Figure 6 is a perspective View of the feed dog, of a lever 36 which is fulcrumed intermediate its 95 lfatenteclA Nov. 14, 1935 y. 'Y 1 I l Y 'Y' l f STATE-s PATENT. omer l Y FEEDINGgMECHANIsM FOR SEWINGL I v MACHINESy Y Horace F, Gruman, St. Louis, Moiyassignor to" Lewis Invisible HStitch -Machinev Company, St. t Louis-,'Mo., a corporation "of Maine l' Original application january 31, 1931, Serial No.I

512.6617. Divided and this application October' ,7. 1.931.. Serial No, 567,487 l This invention .relates to new fand usefulimings '7, 8 and 9 is a needle shaftfll which is oscilprovementsin feeding mechanisms for sewing latedgfrom a rock shaft 12 through the medium machines and2constitutes'fa divisionoftmycoof a rock arm13 fixed to the shaft 12, a lrock pending application Serial No.` 512,661, led Jan. arm 14 fxedfto the needle shafttll, anda link 15 5 31, 1931 for improvements in sewing machines. which connects the rock armsk 13 and 14.6 Fixed ce Among the several objects of this invention to the post is a transverse pivot pin 16 and are to provide a 4-motion feeding mechanism journaled on this'pin is a feed rocker or lever adapted particularly to intermittently feed down- 17. VA feed bar 18 extends longitudinally of the turned edge portions of fabrics Vpast a stitchv work arm 5 and the rear end of this bar is pivg forming mechanism; to provide a vertically disotally'connected by a ball joint 19 to a pivot bolt 65 posed feed dog for cooperation with a vertically 20 mounted in the upper end of the lever 17. vThe disposed presser foot and means for imparting front end of the feed bar`18is providedvwith a backward and forward movements to the feed dog laterally extending fork 21 whose Varms 22,v 22 and lateral back and forth movements thereto; Vare disposed above and below the needle shaft placed within a tubular work arm of comparaneedle shaft and is located. between the arms tively small cross sectional area, and to provide 22, 22 of saidv fork for sliding contact therewith. such a feeding mechanism which is composed The free end of the fork is closed by a cam plate of comparatively few parts and is therefore simor follower 24 which projects forwardly thereple in operation and cheap to manufacture. v from for constantengagement with a peripheral` -75 `With these and other objects in kview which will cam 25 fixed on the needle shaft 11. A coilspring 1 Y more fully appear, the nature of the invention `26 is disposed betweenthe feed bar 18 and the will be more clearly understood by following the slide block 23 and serves to yieldably retain the.V description, the appended claim, and the several cam plate or follower 24 in constant engagement views illustrated in the accompanying drawings.v with the cam 25. A'tongue or rib 27 integral 8o In the drawingsz y with the bracket 6 in the work arm 5 and extend- Figure l1 is a top plan view showingV the applicaing longitudinally thereof, cooperates with a tion of my invention to the work arm of a sewing groove 28 formed in the lower part of the slide machine of the feed-off-the-arm type, block 23 and retains the latter against axial 30 Figure 2 is a vertical longitudinal sectional view movements about the needle shaft 11. A -85 through the work arm, vA vertical feed dog 29 is detachably secured to Figure 3 is a detail sectional view of the cam the feed b ar 18 by screws 30. This feeddog has rmeans for imparting the lateral back and forth its feeding portions 31, 31 projecting into slots movements to the feed dog, 32, 32 in a vertically disposed work guide 33 which 35 Figure 4 is a verticalcross sectional view'taken is xedly secured to the bearing post'34 which 9o on the line 4 4 of Figure 1, i contains the bearings 8 and 9 for the needle shaft.

Figure 5 is a perspective view of the bearing Cooperating with the work guide 33 and also with block on which the front end of the feed bar is the feed dog'29 is a vertical presser foot 35. This slidably mounted, presser foot is fixedly mounted on the upper end Figure '7 is a perspective View of the work guide ends on a needle shaft 11. A Spring 37 iS disposed with which the feed dog cooperates, and betweenthe bearing post 34 and the lower endv Figure 8 is a perspective view of the presser of the lever 36 and functions to yieldablyurge the foot which cooperates with the feeddog and work presser foot 35 toward the work guide 33 and the guide. feed dog29'. Y 100 v Like reference numerals designate correspond- From the f01eg0ng,it Will be apparent that the Y ing parts throughout the several figures of the forward end of the feed bar 18'is slidably supdrawings. portedl on the block 23 andthe rear end is pivot- Referring to the drawings, I have shown my inally Supported by the feed rocker 0I' level 17; that vention applied to a tubular work arm 5 cf a, the feed rocker will impart backward and for- 105 sewing machine of the feed-off-the-arm type. ward movements to the feed doe', and that the Removably mounted Within the work arm 5 is a cam 25 and cam follower `24 will impart lateral bracketv having a front bearing 7, a rear bearing reciprocations to the feed dog. 8, intermediate bearing 9, and a post 10 located A In order to oscillate the feed rocker or lever 17 in rearof the bearing 8. Journaled in the bearand'thereby impart said movements ,to the feed 110 From the foregoing, it will be observed thatthe' lateral reciprocations to thel feed dog. 29 are brought about through the oscillations of the needle shaft 11; that the backward and forward Y of structure and arrangements of parts may be movement of the feed dog is brought about by the oscillations of the feed rocker or lever 17, and that the parts are so timed whereby the components of these two Amovements will result in causing the feed dog to partake of al1-'elliptical path of travel which is generally known in the' art as a 4motion travel. A

Located between the vertical feed dog 29 and the free endfof the work arm is a horizontal 4-2 motion feed dog 41.which1is fixed tonne end of 'a feed bar 42 pivoted at its other ,end to.the upperend of thefeed rocker or lever 17. The feed rocker 17 functions to impart backward and nected to an actuating link 48 which extends along and within the work arm and is operated by the mechanism disclosed in my parent application.

It is of coursevto be understood that the details variously changed and modified without depart'- ing from the spirit and scope of my invention. I claimt-.- 4 In' a sewing machine, the combination with a front vertical 4-motion feed dog, of a rear horizontal 4-rnotion feed dog, means including a single feed rocker for imparting back and forth movements to both dogs, and means for imparting horizontal reciprocations to the front feed dog and vertical reciprocations tothe rear feed dog. HORACE F. GRUMAN. 

